CN104269019A - Interactive Magnetic Marker Field For Safety Systems And Complex Proximity Warning System - Google Patents

Abstract

The invention relates to a complex proximity safety and warning system. The invention provides a safety system comprising a generator that generates a magnetic field that establishes a boundary, where the generator is capable of receiving radio frequency signals. Also provided is a radio frequency device that sends radio frequency signals, the radio frequency device being capable of sensing the magnetic field and generating a radio frequency response. In the safety system, the generator generates the magnetic field for a first predefined time period, and thereafter senses for a radio frequency response signal from the radio frequency device within a second predefined time period. The invention also provides for shaping safety zones by overlaying magnetic field boundaries to produce a different boundary. The invention also provides for varying the strength of magnetic fields by adjusting a width of a timed pulse.

Description

For magnetic marker field and the complex proximity warning system of the interaction of security system

To the cross reference of related application

This application claims US provisional application No.60/996, the rights and interests of 034, wherein inventive concept is combined in herein by reference.

Technical field

The present invention relates generally to the security system in working point, and in particular to the magnetic marker field of interaction with close to warning system.Design many methods to be clashed into by vehicle and mobile device to protect people to avoid, clamp, extrude or other injury.Such vehicle and mobile device can be used on the ground or sub-terrain operations.The example of equipment comprises: road construction equipment, such as truck, road machine, street roller and paving machine etc.; Strip mining equipment, such as, for gravel and husky that operate, front end loader, truck, dozer, conveyor and sundry item; Underground mining apparatus, such as continuous miner, shuttle car, conveyor, disintegrating machine, scraper, Personnel Carrier (man-trip), tractor and sundry item.Equipment is also included in fork lift truck that warehouse and shipping port use, crane and truck.

Background technology

Hundreds of people is killed by such equipment every year in the U.S..Unfortunately, having designed the system (such as close to protection and collision avoidance system etc.) protecting people and property in these industrial operations is not very effective usually.Be sometimes referred to as new being developed close to protection system and successfully proving to use on continuous miner of collision avoidance system, as disclosed in U.S. Patent application publication 2006/0087443, it is incorporated into herein by reference of text.The object of ' 443 publication prevents the personnel of remote control continuous miner be extruded or peg, and the other staff using continuous miner are assisted in protection.' 443 publication is also imagined provides protection to exempt from the mobile device of other types and the injury of machine to personnel.The system of ' 443 publication adopts magnetic marker field and active tectonics, and it comprises the duplex communication between machine that protected people and protection people exempt from its injury.Workman to dangerous close coalcutter warns.Warning is also supplied to the operator of machine.Executive measure is to enable equipment fix until personnel arrive home.

But ' 443 publication does not provide completely enough structures for there being many personnel to close on the environment of multiple equipment work in identical work space.Such as, it is essential that the signal of system or response are only for the machine of safety and/or the operator of this machine that threaten workman.Otherwise, from the signal of system or response by the unnecessary signal that causes other impregnable machines and/or workman or response.Unnecessary signal like this or response cause useless false alarm.It is many close to protection system and the main cause failed in true operation environment of collision avoidance system for having known false alarm for many years and having created disturbances to alarm.

False alarm is the main cause close to thrashing of disposing with creating disturbances to alarm traditionally.In real industrial environment, experience mistake and the problem of many forms of the shape relating to protection zone close to system.Such mistake and problem are discussed in the NIOSH Report RI9672 of " the Recommendations for Evaluating & Implementing Proximity Warning Systems on Surface Mining Equipment " by name of Department of Health and Human Services.

When alarm is sounded and do not had a real hazard, the example of occurrence can retreat alarm about the standard of the laws and regulations requirement by most industry vehicle and illustrate.When vehicle or machine start to retreat, warning horn typically sounds.In the working environment having many vehicles or machine, many warning horns are typically had to sound very continually.Such warning horn is ignored by workman very soon.This is because stop for each workman consider that each warning horn sounded in their perform region is unpractical.Even if ought only have a chassis, if this vehicle retreat continually and workman hear continually warning horn sound know simultaneously they safety do not threatened, workman will start to ignore alert device or alarm very soon.So when their safety is really on the hazard, warning horn does not provide protection, because workman can ignore warning horn, believe that it is another false alarm.Thus workman should only be warned when there is the threat to them.

Before close to and collision avoidance system also avoid giving alarm connection not being effective when only reliably warning the realistic threat of safety when real hazard not to workman.The analysis of prior art collision-warning system is discussed in the publication from SAE International of No.2007-01-4233 " Development and Testing of a Tag-based Backup Warning System for construction Equipment " by name.For only a machine and workman have been found that Shortcomings in the working point of operation.These deficiencies are middle in complex work region (region comprises many key elements) amplifies.Another has been in exploitation close to protection concept and has used in working point; such as in road construction place, strip mining transformation, the use such as entrucking parking area (loading dock); wherein multiple machine and vehicle closely collaborative work each other routinely, and wherein work in the region of many workmans around machine.Based on test, have realized that the needs of the hazardous location that restriction is limited, make workman can not produce alarm in side or above near vehicle.

Another challenge of security system is that the operator of vehicle and equipment may get off and/or leave their equipment in operation continually.Existing close to protection security system do not distinguish situation when operator is in the vehicle taking him or machine (wherein system should not produce warning or the situation making vehicle motionless of taking action) and wherein operator get off and move at vehicle periphery and at this moment need the situation to operator's general protection.

Consider the fast development of radio-frequency (RF) identification in world wide (RFID) technology, considered to use RFID technique and scheme for close protection.The major defect of RFID technique is used to be that the method dependence is transmitted with the radio frequency of the high frequency in electromagnetic wave spectrum (RF).Because the maximum magnitude of some types of RF system is almost unlimited, if need nearly several miles, due to this reason it may the good candidate of seemingly collision avoidance system, especially when vehicle travels at a relatively high speed.Equally, higher frequency can provide much bigger bandwidth, and it allows to realize many special functional characters.But, in complex work environment, there are metal material and the surface of many reflect RF signals, cause RF signal to propagate over a plurality of paths.If RF receiver is for measuring the intensity of RF signal, to determine the distance between vehicle and people to be protected, then these reflections over a plurality of paths can cause mistake in the measurements.Radar system is easy to the most of any object (even if object does not threaten safety) be identified in the hazardous location of restriction.Gps signal also has been found that by the reflections affect of neighbouring equipment, causes the erroneous calculations of the distance between receiver and vehicle.Thus, reliable Label Field (such as safety zone) can not use high-frequency RF system held.In addition, RF signal is not easy to pass through earth formation; So, personnel may be shielded in outside security system protection until too late and can not take to withdraw action.Even intermediate frequency magnetic field has been found that and to propagate on cable and pipeline, makes intermediate frequency magnetic field more unreliable than what expect.

Contrary with RF field, known with the magnetic field of low frequency oscillation is stable and can effectively for marking place of safety or hazardous location.Such technology is giving the U.S. Patent No. 6,810,353 and 5,939 of Schiffbauer, discusses in 986, and they are incorporated into herein by reference.The maximum actual range of the low frequency magnetic field of even now may be less than 50 feet in most applications, and it is greater than most of equipment needs or desirable.Typical haul truck preferably may provide the warning zone in 20-30 feet and the hazardous location in 10-15 feet.In some applications, such as remote control continuous miner, the scope that operator remains on 10-25 foot the most of the time is interior so that it is necessary for keeping contacting with the good visual of adjacent environment with machine.In underground mine, magnetic field unhinderedly makes the workman around corner (not in sight line or stopped in addition) will remain visible for Label Field by earth formation.These magnetic fields do not send from antenna and are producing their component ambient enlargement and contraction simply, and are applicable to well mark the border between safety zone and insecure area.Make and having attempted using application identification information (ID) to magnetic field as the part close to protection or collision avoidance maneuvers.But, there is serious restriction for the method, especially when working point includes many key elements (machine, workman etc.).Be limited in the bandwidth of low frequency, thus the process that typical case adopts by restriction.If two adjacent machines send their ID, low-frequency field potentially conflicting simultaneously, and cause the changes in amplitude of synthesis field, thus cause the mistake of data centralization.Utilize lf marker field, available bandwidth is not enough to allow to resend data set fast and use algorithm to remove mistake.Have many possible interactions between many key elements, situation wherein may be left in the basket sometimes, but may be also crucial to safety.

Conflict between the field produced by multiple system easily occurs.Workman may find they control oneself more than one machine magnetic field in and the coordination of system responses may be lowered and be insecure.Such as, if for warn safety of workers to threaten corporally personal warning's device in two hazardous locations of two machines, and one is larger threat, then personal warning's device must can determine which is biggest threat and correspondingly responds.Meanwhile, the operator of machine needs the alarm be applicable to giving this machine, instead of to the alarm that the second machine is applicable to.When having three or four machines closely working together in same area, the workman crucially near each and each operator do not receive the instruction making us obscuring.If alarm is made us obscuring, this security system will not used.It is desirable that can reliably adapt to the environment with multiple mobile key element close to system.

Also need and send information with the method for recording events (security-related event such as experienced) from each workman, to allow use system such as tracking personnel during emergency condition.Also need the parts of the data that position and the safety of collecting and relating to individual workman is provided.In addition, the response that can provide interaction to equipment and/or operator is needed for workman.

In addition, although low-frequency field is for marking protection zone or hazardous location is desirable, because they are highly stable, this stability of vpg connection on the scene is disadvantageous in some cases.Such as, exist and expect workman near equipment in the situation that another position is not close position.Example is the truck retreated.There is low-down risk the workman of the side of truck or risk may do not had at all; But the workman after truck may have very high risk.But, extend enough far away from the larger field providing the magnetic field of the protection of needs also will to produce the side of truck than expecting after truck.Therefore also need to make Label Field shape change into and get rid of the region that workman's needs are positioned at and/or the region such as not occurring security risk.In addition, it is desirable that a kind of special system and be configured to reliable close to warning or collision avoidance system, it will avoid the many danger existed in many various industrial.

Summary of the invention

The applicable working environment of the present invention is very various.Length herein does not allow to describe all these application.One in these environment, road construction environment can be used as the basis describing important and novel feature of the present invention.Then some workmans in road construction place may temporarily move to different machines at particular machine surrounding work or work on when another machine arrives.Some workmans may move by the space between machine continually.But other may to ride on vehicle but also may be switched to another vehicle from operation vehicle.Further, some machines can by workman's remote control.Sound must consider close to protection system and can reliably keep safety of workers to process all such performance variables simultaneously, and does like this and do not have great false alarm or warning.The present invention meets these requirements.

When equipment and personnel's collision free of claimed all movements, complicated working environment proposes larger challenge to close to protection system.When there being multiple workman in the zone, it is basic for not disturbing, interrupt or obscure system to the action of other workmans to the system responses of a workman.Therefore, warning or alarm are not only important for other workmans for the workman needing such alarm.Like this, the workman of operator or association will know, when they receive alarm, alarm is intended to remind them to take certain action to avoid or to evade danger clearly.

In one embodiment, the invention provides security system, it comprises the generator producing and set up the magnetic field on border, and wherein generator can received RF signal.Also provide radio-frequency unit, it sends radiofrequency signal, and this radio-frequency unit can sense magnetic field and produce radio-frequency responsive.In this security system, generator produces magnetic field during the first predetermined amount of time, and in the second predetermined amount of time, senses the radio-frequency responsive signal from radio-frequency unit after which.

In another embodiment, the invention provides the secure border of security system for generation of shape.This security system comprises the first generator producing and have first magnetic field on the first border, and produces second generator with the second magnetic field of the second boundary.According to the present invention, overlapping first and second borders produce different borders, and the first and second magnetic fields produce in order.

In more another embodiment, the invention provides the magnetic field generator for security system, comprise the magnetic field generator controller for generation of the timing pip of concussion and the amplifier for the timing pip that amplifies concussion.Generator also has winding and ferrite, and the timing pip of the concussion of wherein amplifying produces by winding and ferritic electric current, thus creates the magnetic field with intensity.According to the present invention, the intensity in magnetic field is by regulating the width of timing pip to be variable.

Accompanying drawing explanation

Above and other advantage of the present invention and feature are clearly understood from the following detailed description provided together with accompanying drawing.

Fig. 1 illustrates the exemplary work point according to an embodiment of the invention with security system.

Fig. 2 illustrates the schematic diagram of Label Field generator and personal warning's device according to an embodiment of the invention.

Fig. 3 A-3D illustrates the vehicle having according to an embodiment of the invention and be suitable for the security system making Label Field shape.

Fig. 4 illustrates the Label Field of the shape of illustrated security system in Fig. 3 A-3D.

Fig. 5 illustrates the schematic diagram of Label Field generator according to an embodiment of the invention.

Fig. 6 and 7 illustrates the sequential chart of the communication according to an embodiment of the invention between safety system components.

Embodiment

The present invention personnel that can be applicable to especially to require close on the working point of various dangerous key element (vehicle etc. of such as machine, mobile device, remote-controlled machine and operation).It is inherent dangerous and the position should avoided or can only enter very carefully that such working environment can comprise.The example of such working environment is strip mining transformation, underground mining, gravel and husky operation, road construction, warehouse, shipping harbour, coke-oven plant etc.Workman is sometimes knocked when carrying out their work in this environment, presss from both sides, extrudes or injures in addition.Collision between the various key element in working point needs to avoid simultaneously to avoid property damage.

The present invention by use novel method and the device for putting into practice the method overcome restriction of the prior art for generation and coordinate magnetic marker field and for by RF transmission response in magnetic marker field.Security system of the present invention also provides specific function, these functions make security system more reliably, more user-friendly, more multiduty and inherent system capability can be utilized to provide other benefits.

As disclosed herein, various protection zone can shape configure with applicable concrete equipment or perform region.Thus it is possible for producing the safety zone with intended shape.In addition, importance of the present invention is the method and apparatus operating into chopping magnetic marker field, and each pulse is made up of low frequency oscillation.Pulse is referred to herein as PING.Device also operates in response to PING pulsed RF transmission, and it is referred to herein as ECHO.The typical pulse (PING) in magnetic field such as will produce 73 concussions of field during 1 millisecond.The typical pulse (ECHO) of RF response such as will produce 229,000 circulation during 250 microseconds.

The present invention is sound, provides warning system very reliably.Except when dangerous time provide outside alarm or the necessity of taking action, when being safe from danger, security system of the present invention does not produce false alarm.System before great majority provides significant protection to exempt to obtain in multiple machine injury to many people and seldom or not makes progress in the general area of identical restriction.PING/ECHO system described herein reliably provides almost error-free warning in real industrial environment (comprising complicated equipment and personnel's setting).

The simplification example of the working point realizing embodiments of the invention is shown with referring now to Fig. 1, figure.Fig. 1 illustrates two vehicles 20,40 and three Label Field generators (MFG) 22,44,46.Fig. 1 also illustrates three individual alarm devices (PAD) 30,32,34, and it is carried by workman A, B, C.Fig. 1 also illustrates workman D, carries PAD36, and this workman D is at operation or steering vehicle 20.

MFG and PAD is the primary element of PING/ECHO system and describes in more detail with reference to Fig. 2.MFG80 illustrates to have microcontroller 82, and it produces low frequency oscillation, and it is amplified by amplifier 84.Low frequency oscillation produces the low frequency oscillation electric current by the winding 86 around ferrite 90.Capacitor assembly 88 and winding 86 are connected in series to produce and shake magnetic field.Select the value of the capacitor in capacitor assembly 88 to produce with the series resonant circuit of the operating frequency of PING/ECHO system.Typical circuit will comprise the inductance value of about 300 microhenrys of the electric capacity such as with about 163 microfarads.The use higher electric current of less driving voltage generation by winding 86 of series resonant circuit of the present invention.

Then magnetic marker field 92 produces around magnetic marker field generator 80.Magnetic marker field 92 is with the operating frequency selected expansion and decay.Such as approximately the operating frequency of 73kHz has been found that it is suitable selection.Have the knowledge of instruction disclosed herein, the people be expert in the application of magnetics, tuned circuit and plan can select operating frequency and circuit component to be applicable to concrete application.Such as, operating frequency can be reduced to 25kHz (if L/C ratio and be greater than for the rise time desired by the system responses required for driving the voltage of lc circuit not cause).Higher frequency higher than about 100kHz should be avoided because they are easy to propagate on cable and pipeline or by other metal objects in underground mining.

Personal warning's device (PAD) 60 is also shown in Fig. 2.PAD60 has three quadrature coils 62, its sense marked field 92, and and then enters detection circuit 64 by signal/information that wave filter 66 and amplifier 68 transmission sense.The intensity of microcontroller 70 measuring-signal, and there is battery 71.Microcontroller 70 opens RF transmitter 72 to be sent return signal 76 (ECHO) by antenna 74 to the receiver antenna 94 in generator 80.Then ECHO signal 76 is delivered to MFG receiver 96, and it is registered the existence of ECHO and sends suitable response/information to microcontroller 82.

In use, MFG microcontroller 82 determines whether receive ECHO76 in response to the PING92 sent by MFG80.The safety zone at the PAD place of launching ECHO also determined by MFG microcontroller 82.Alarm signal is sent to the warning system 98 be positioned near vehicle operators and/or on vehicle.Alarm signal is that can listen and/or visible for affected workman.Shell 81 for the MFG80 shown in this configuration can be explosion-proof type, it maybe can may be had in other application of explosion environment at underground coal mining and use.Other details (comprising such as shell how to construct) about MFG and PAD are open in the publication of ' 443, and are incorporated into by reference herein.

Referring again to working point shown in Figure 1, between factor of system, there are many possible cooperations and potential destructive relationship (even if for this simple examples).Owing to having more key element, what may be related to increases in numbers swiftly.True operation environment usually comprises many MFG and many more PAD.Such as, owing to having four vehicles or machine, other workman of four operators and four, between various PAD and the multiple safety zones produced by MFG, hundreds of relations and possible conflict is had.Such as, if all Label Fields are by chopping continuously, the Composite Field so between any some place Label Field is these vector.If Label Field also comprises any ID or set of metadata of similar data, it can be overthrown by other Label Fields or cause and the conflicting of other Label Fields, thus produces mistake.PAD must can measure any Label Field in the Label Field at their places, measures them to know which system (MFG) produces this Label Field, and only in response to the Label Field that should respond.

Such as, consider shuttle car just near continuous miner to load the situation in colliery.Shuttle car near continuous miner until it contacts with coalcutter, must have significant overlap between the Label Field that two machines are produced.May conflict be had between Label Field, itself so that be debatable for the PAD used just in those regions.If these interference or PAD can not in response to two machines, then workman will not be fully protected.

The warning of security system suitably corresponds at least two-stage and threatens, and give priority for the most serious threat, this is very important sometimes simultaneously.Such as, two area grades are limited by magnetic marker field in FIG.Warning zone 28,58 is the regions avoided, because danger is close.To be workmans will to be in imminent danger in hazardous location 26,56 and should move at once and emergent stopping feature on his PAD (such as) maybe should be used to stop the region of machine compared with home.In addition, monitor area 24,54 may be used for reminding workman that they are being equipped with (even if they are not at stake and can not receiving alarm) near the machine close to protection.Other additional areas can be defined the function allowing to perform other, such as, authorize PAD to send data for recording from the system of PAD at sensing or the information of environment.

Some of the situation that security system must be able to process are illustrated as follows.With reference to Fig. 1, the workman A carrying PAD30 and carry PAD32 workman B at first at the rear portion of vehicle 20, as shown.Then the workman B carrying PAD32 shifts out from hazardous location 26 and enters the monitor area 24,54 of vehicle 20,40.Meanwhile, the workman C carrying PAD34 leaves the pilothouse of his vehicle 40 and moves to the hazardous location 26 at the rear portion at the first vehicle 20 from hazardous location 56, to add other two workmans A, B.In order to these changes that completion bit is set up, workman B, C are through multiple safety zones (Label Field) of two vehicles 20,40.Carry the workman C of PAD34 through at least four regions, and simultaneously through the region of two vehicles 20,40.

Not only must the magnetic marker field of two trucies 20,40 not conflict, and PAD30,32,34 must not with each other or MFG conflict.System can be recognized has workman in their hazardous location 26,56, and if do not have so whether there is workman in their warning zone 28,58, this is important.According to the present invention, PAD30,32,34 warns workmans and the driver of system alert truck, and neither one safety system components shields or obscures another.System of the present invention (it comprises such as PING/ECHO technology as discussed in detail below) allows all these quick generations and not conflict that interact.

In the publication of ' 443, the verified concussion magnetic field with low frequency operation is provided in the Label Field of dimensionally stable.Also known such low frequency oscillation field will penetrate most of material, comprise earth formation; But, emittance can not make there is no Multipath reflection.Lacking radiation is because the size of generator element is very little compared with the wavelength (shake for 73kHz and be greater than 4000 meters) of field.From using another benefit of non-radiative magnetic marker field to be the intensity in magnetic field and cube inversely proportional change of the distance of generator of leaving the theatre, by contrast, the RF from antenna launches square inversely proportional reduction with distance.This cubic relationship reduce with the amount of collisions of Label Field near other (as the RF Bob with radiation comparatively), and the accuracy that permission is larger when determining the distance from sensor to generator.

The invention provides reliable and accurately method for allowing the compatible and cooperation each other of the key element of many activities.The method is with controlled, that half randomized mode produces magnetic field short pulse in one embodiment, and PAD or TAG of those pulses of sensing of carrying from workman obtains response.By producing short pulse (when producing PING) with half randomised way, timing window is set and by using randomizer to select concussion in this timing window by specified point during generation.Equally, if send the burst (burst) of PING, can produce ECHO burst in response to this, the time interval between these PING can be little timing window, and on the duration, it can be only such as several millisecond.The system of setting makes will not damage proper operation from multiple ECHO of multiple PAD and the reflection of these ECHO.In addition, in system, provide dirigibility to allow to provide important specific characteristic.Such as, replacing producing single PING, several PING can be produced continuously by multiple generator, and PAD can sequencing to wait for until received all PING before to the decision action taked being made logic.

There are the various special circumstances that must consider.Such as, if workman is between two vehicles, nearer or more dangerous vehicle necessarily can not be shielded to the vehicle that workman does not constitute a threat to.Key is also had to be that operator has known whether that any workman is potential on the line, and no matter has how many workmans in perform region.Further, if closedown or deceleration feature are just used by machine automatically, system also must can determine whether the potential danger grade that any situation has reached such.In order to complete these and other critical functions, the parts of security system logic function is provided and fast and reliable communicate.This is by using the combination of short duration PING and short duration ECHO, implementing narrow duration window for receiving PING and sending ECHO, random time generation and make logic decision at the two ends of message exchange and complete.

PING/ECHO system provides sound basis to the system capability required.PING is short and with the transmission per second of semirandom mode repeatedly, makes PAD receive PING from many sources if having time on the duration.If PAD is in warning or hazardous location, it is conveyed through ECHO to respond the information in the region at instruction PAD place via the RF of the specific duration at special time.The each system producing PING also has current alert state, and it represents security system and knows that workman is in protection zone.If PING/ECHO sequence has occurred and has pointed out the alert level higher than current alert state to system, system can produce before entering higher alarm state two or three or more the fast-pulse that exchanges of PING/ECHO to burst to confirm that initial PING/ECHO exchanges be correct.Burst Mechanism Design becomes avoid vacation or create disturbances to alarm.If PING/ECHO sequence fails acknowledgement state, process can be repeatedly per second.

Because these PING send out with half random time intervals, two MFG can produce PING overlapping in time, and this is possible.If PAD is in these MFG near two, it may be misread field intensity and may respond and produce wrong ECHO.Burst confirms that sequence (wherein multiple PING is as one group of transmission, but is separated by short fixing or random time section) is designed to the statistical likelihood greatly reducing false alarm signal.PING and burst confirm sequence to be randomized to such degree so that system, and to enter alarm state be mistakenly extremely impossible (even if some systems are near operating each other).Such as, complete once a PING/ECHO exchanges, three pulses can be sent, and condition is interval between pulse selects randomly from the manifold of the range between 250 microseconds and 5 milliseconds.

The importance of PING/ECHO system all PAD (or TAG) in given work complex environment can be made to respond in an identical manner some maybe can be made to respond in a different manner.Some groups response in an identical manner of all PAD or PAD in perform region is made to provide advantage.Such as, they can sequencing make will strengthen each other from the signal of the multiple PAD be accidentally in same area simultaneously separately.Utilize the method, the workman carrying PAD can move to another from a working point in this complex environment, and guarantees the protection with same levels.But in the place requiring special circumstances, PAD can sequencing and system on machine can sequencing uniquely uniquely.Such as, if truck just protected avoiding is fallen in dell on roach, PAD can be attached to when truck back to expect to dump some time be the bar of position in hazardous location.It can be arranged to sense the field produced by the inductor at truck rear portion.Inductor at truck rear portion typically will limit hazardous location.The sensitivity of this PAD can need to be arranged in the different scope of other PAD worn by workman, although this is unnecessary.Needs are considered this situation and operation scenario.But, PAD can also sequencing with only in response to the generator at truck head, this generator arranges the field that will have and extend near the last axletree of truck for typical PAD.PAD will know the front portion of which generator at truck due to known sequence (wherein will produce (Typical Disposition) fields by three generators).But this must completing of extreme care make the use of standard configuration PAD provide identical protection by continuing.

In a few thing region, the side of the necessary close vehicle of workman or machine, but should not be in (at least when they retreat) after these vehicles or machine.Make Label Field narrow in these cases to make workman can not to be enabled in alarm on their PAD or alarm operation person closer to the side of vehicle, this is helpful.Because the shape that low-frequency magnetic Label Field key property is them be easy to be very predictable with constant, from the viewpoint of practice, these shape can not turn to and narrow in the side of vehicle or machine.The present invention discloses the use of multiple Label Field generator to change the shape of Label Field.The method changing the shape of magnetic marker field is by making the one or more phase place in multiple generator reverse.Can by considering can not the simultaneous fact to complete according to Label Field of the present invention to the more multi-control of field shape.By requiring that PAD is in the same area of two generators, the shape in this region is reduced to these overlapping scopes, because the scope of the overlap of these two generators between these generators is less.If these the inductor produced is such as in the back corner of truck, so overlapping field by centered by the rear portion of truck and their width the intensity by field determined and PAD to its sensitivity sequencing.

In addition, this requirement can be placed on PAD, and it is by using software to get rid of overlapping range (area of overlap) from this region in the microcontroller.By in conjunction with the logical capability in PING/ECHO method and microcontroller, complete the significant shape of protection zone.Such as, the region that truck retreats can start near the rear portion of truck and extend with arrowhead form in the back of truck.This produces the ideal zone of protection.The rear portion general of outrunner person and backboard is not in alarm region and driver will in alarm region.

Multiple Label Field can take same space by limiting each to short duration, generation pulse or PING, and this pulse or PING such as can be only about 1 millisecond on the duration, and it is 73 circulations that about 73kHz shakes.Because there is the possibility that two generators closing on can be accidentally synchronous, the PING from these generators is simultaneously or almost simultaneously occurred, the duration between PING is Stochastic choice (Fig. 6 and 7) in time window.Like this, if these generators are accidentally synchronous, the possibility of the conflict between the ECHO of response reduces greatly.

The ECHO of the form that the employing RF from other PAD that known problem is in response to other PING transmits can be accepted as ECHO (Fig. 2) mistakenly by MFG80.In order to solve this problem, the receiver 96 in MFG80 find specific time window (such as at the time window sending after PING one or two millisecond) period occur return ECHO.In addition, predetermined time delay is implemented before can starting with special time window after transmission PING.Like this, in order to make the stray pulses (strap pulse) from other sources be accepted as response ECHO mistakenly, it must appear in the window of accurately restriction.

But the still wrong possibility that can occur, even if this possibility is little.RF signal in order to ensure reception is effective ECHO, and system of the present invention can operate into and send a series of PING in burst, then receives and analyze corresponding ECHO.The PING of this burst was executed quickly before next PING window can obtain from any other MFG (it may send PING) simultaneously.In the same area of two the MFG systems of PAD on two vehicles or machine, and they also enter moment in the region of these two MFG systems accidentally synchronous unlikely situation at PAD under, PING/ECHO burst sequence will be rejected.But whole process will restart in next PING window, at this moment the next random PING (after typically between 0.050 and 0.250 second) produced will be sent.This whole sequence again simultaneous minimum possibility is so little so that it can be left in the basket.In order to confirm that ECHO is effective, above-mentioned sequence can repeated several times very fast.If do not received as expected, unless microcontroller 82 supposes that initial ECHO is invalid and the PING no longer taken action subsequently produces effective ECHO all response ECHO of the repetitive sequence of PING.But if ECHO is confirmed to be effective, microcontroller 82 is programmed taking it the action that will take.

Use the burst of PING within the time period selected, to produce PING to guarantee ECHO to be effective alternate strategies be on a random basis, and require that the sequence of PING and ECHO is received and completed valid reading and response to set up.Equally, the timing window set up for receiving ECHO can be the variable possibility to reduce to be interpreted as from the noise in other sources PING or ECHO further in a string PING/ECHO exchanges.The length of PING and ECHO and receive window also can represent dangerous different brackets response sequential and/or the duration changes.Once PING/ECHO system the PING of making constructed according to the invention to be produced by magnetic marker field and ECHO is returned by RF link, the various combinations at the interval between the sequential of transmission and duration and transmission can be adopted.

Therefore, can recognize that any generator can produce his Label Field and not disturb another.Also draw thus, ECHO reliably can point out that PAD does not conflict in warning zone, hazardous location or other localized areas.Then microcontroller 82 in MFG80 such as the ECHO of PAD reliably always in comfortable hazardous location can give the priority that priority exceedes the PAD given in warning zone.

Certain versatility of PING/ECHO concept can the mode of shape be proved by protection zone or hazardous location.Be there is by the magnetic marker field using ferrite to produce the shape of the xsect being approximately ellipse.As explained above, Label Field is stable and reliable, and keeps its shape.But if use multiple generator, the shape of the Label Field of gained can be changed by technology disclosed herein.Two generators can be used to overlap Label Field, and be timed not occur at synchronization.By the PAD that uses in such working point then can sequencing with only when PAD alarm in the region of these two generators, namely only when PAD senses the PING alarm from two or more generator.If needed, it is possible for main equipment having three or more generator to produce even more restricted field.In addition, the field of these overlaps can be adjusted to and have different intensity to change the shape in region further.According to the present invention, the adjustment of these the intensity produced by each MFG can complete by regulating the width being driven through the pulse of the electric current of generator.To the microcontroller programming in PAD to have different sensitivity to MFG field, it will regulate the size of field, and regulate the size and dimension of the hazardous location on vehicle or machine thus, this is also possible.Microcontroller outputs signal generator and makes these opposite each other and do not strengthen to produce special field configuration each other, and this is also possible.Three or more generator can be used to limit further or to change protection zone or hazardous location.

The example of the validity of region shape feature is shown in Fig. 3 A-3D and 4, and the effect wherein combining the Label Field of three generators illustrates in order.These figure prepare based on actual test data and the test organized by inventor.Fig. 3 A illustrates the vehicle 120 with anterior 122 and rear portion 124.In figure 3 a, warning zone 102 and hazardous location 104 are by MFG100 chopping or otherwise produce.MFG100 is positioned at the left back portion of vehicle 120.In figure 3b, MFG140 is shown, it is positioned at the right back portion of vehicle 120.MFG140 creates warning zone 142 and hazardous location 144.Then, Fig. 3 C illustrates the overlapping range being produced Label Field (as illustrated in figures 3 a and 3b) by generator 100,140.In an embodiment, those overlapping ranges are avoided by workman.Fig. 3 D illustrates warning zone 172, hazardous location 174 and safety zone 134, and it is built by overlapping mark field.Warning zone 172 and hazardous location 174 are by creating in the warning zone 102,142 that requires PAD to determine its both MFG100,140 whether on the rear portion of vehicle 120.Similarly, PAD will determine it whether in two hazardous locations 104,144 of those generators.Safety zone 134 creates by regulating the intensity of the field produced by the MFG130 on the front portion of vehicle 120 position making warning zone approximately arrive the 3rd axletree (axel) of such as truck.

The shape region completed of security system is shown in Figure 4.Fig. 4 illustrates complete shape region, adds the place of safety 134 produced by the 3rd generator 130.In shape region, place of safety 134 is got rid of from the danger and warning zone of the overlaps by MFG100,140 establishments.Recognize the certain strength of the place of safety 134 created by MFG130 by making PAD recognize Label Field by the sequence of chopping (such as, place of safety 134 will be the 3rd PING sensed by PAD) for getting rid of a technology of place of safety 134.Fig. 4 illustrates three workmans 162,164,166 near vehicle 120 and driver 160.Illustrate that (and electrical connection shown in Figure 5) two magnetic marker field generators 100,140 of installation have been placed on the rear portion 124 near vehicle 120.From the shape of the field sub-elliptical roughly indicated by zone boundary 182,184 of these generators, but they are combined into and limit warning zone 172 and hazardous location 174.These regions 172,174 should be avoided, unless the workman in the position of workman 166 is really safe from danger and may needs in that position.Novel aspect of the present invention increases the field representing safety zone 134, and it may be used for the effect replacing overlapping hazardous location, but is only being known as in safe region.If PAD is in the warning zone of the particular field produced by particular inductor, this understanding is in the region of other generators for ignoring.Therefore, if the field producing in certain direction and be greater than expectation is intersected in two hazardous locations, the use of the 3rd generator allows the size limiting this on the direction of the 3rd generator.

As previously described, the sensitivity of the power of overall dimensions by input generator of the field produced by each generator and the PAD by probe field is determined.Power input and PAD sensitivity can such as be regulated by the change in software.The change to these parameters made by software can by being used in switch on PAD or using by signaling to make the switch activated of such adjustment to microcontroller.During two generators 100,140 at the rear portion of truck limit warning zone 172 and hazardous location 174, the 3rd generator 130 limits safety zone 134.3rd generator 130 illustrates and is positioned at before other generators 100,140, near the front portion 122 of truck 120.It also can be positioned at other positions forward.The Label Field produced by the 3rd MFG130 limits safety zone 134.When in this region, by the alarm (such as workman 166 or operator 160) not from PAD.The region that the rear portion being limited to truck will be avoided and limited backboard safety zone forward, the shape region that will avoid making gained is desirable.

Now, how the chopping illustrating from PING/ECHO system is combined with the chopping from PAD works.The actual setting of block diagram trace system parts shown in Figure 5 to produce hazardous location and the place of safety of shape, described above.Microcontroller 202 typically produces 73kHz and shakes waveform during one millisecond.Although the duration of the frequency of concussion and the pulse of concussion can sequencing, they must very accurately control.Microcontroller 202 determines in pulse train, need which inductor 204,206,208 and transmits a signal to the amplifier 210,212,214 associated with this inductor.Then these signals are amplified and the electric current of gained is sent by the tandem compound of capacitor assembly 216,218,220 and inductor 204,206,208.

Capacitance component 216,218,220 can comprise regulate with allow circuit be tuned to resonance to maximize the output of field.Or they are adjustable to make circuit off resonance to reduce the magnitude of current, thus reduce the size of Label Field.As previously described, the width of the waveform of amplifier can be sent to by sequencing by the average concussion electric current of tuned circuit and regulate.To measure by the intensity of the field of both MFG100,140 generation with reference to Fig. 4, the PAD worn by the workman 162 being positioned at region 172 and determine that it is just measuring the field intensity from both MFG100,140, it indicates it in both warning zone.Pulse from MFG is produced by the microcontroller 202 in MFG Control Component 200, is amplified by amplifier 210,212,214, then releases around inductor 204,206,208.These pulses are produced in order by these three inductors, make to put at any time an only inductor and are producing Label Field.These field pulses are PING, as discussed herein.

When the PAD worn by the workman 162 illustrated in cross-hatched area 172 determines in its warning zone at both generators, its prepares warning and carries the workman of this PAD and send warning to the operator 160 in vehicle.But this PAD also checks to determine it whether in safety zone.The alarm and can LED be lighted if not, it sounds, and send signal to sound audible alarm 222 and light LED224,226, with alarm operation person PAD in warning zone to operator 160.If it is in the warning zone of the 3rd inductor, such as, in the position of PAD166, instruction workman towards in the danger of advancing too far and not on be afterwards retracted back into below of truck, is meaned that it is in safety zone 134, and therefore will not arrange alarm by it.But because PAD is to the rear portion of truck, it can not determine that it is in the field of the 3rd inductor, therefore it will to sound alarm (be can listen and visibly) to workman, and can listen and warn trucker 160 visibly.

Now, the 3rd PAD worn by workman 164 is considered.For the configuration illustrated in this illustration, there is the scope of the hazardous location overlap of two generators at rear portion, show for dual crossing hachure, and PAD164 is arranged in this region.PAD will sound hydropac and be enabled in alarm in the pilothouse of vehicle (audible and visibly).When PAD164 finds the PING from the 3rd generator 130, it can not be seen because field, place of safety has been adjusted to after truck 124 to former feet of end.Therefore, it will in hazardous location 174 time action, warning workman 164 and the driver 160 of warning in pilothouse.

The exemplary diagram of the communication between MFG and PAD is shown in Figure 6, and its center line M1, M2 and M3 describe the output (pulse) of MFG1, MFG2 and MFG3 respectively, as each MFG sends PING190.Line P1, P2, P3 and P4 illustrate the output of PAD1, PAD2, PAD4 and PAD4 respectively, and this output is VHF radio frequency ECHO192.In this example, all three MFG can from all four PAD Received signal strength, and vice versa.MFG1 finds the existence of ECHO signal between the schedule time window phase of mark W1A and W1B.MFG2 finds the existence of ECHO signal during the time window of mark W2A and W2B.Further, MFG3 finds the existence of ECHO signal during the time window of mark W3A and W3B.

In the example shown in the series of figures, PAD1 sensing from the PING190 of MFG1, measure signal intensity and determine that it is in hazardous location, and by its round-trip impulse response on VHF channel after predetermined time delay.Exemplary predetermined delay is about 1 millisecond, but can up to about 10 milliseconds, and this depends on that other are considered.PAD2 sensing from the PING190 of MFG1, measure signal intensity and determine it also in warning zone, and responding by launching ECHO on VHF channel afterwards at predetermined time delay (they can be different from the predetermined time delay of PAD1).PAD3 sensing from the PING190 of MFG3, measure signal intensity and determine that it is in hazardous location, and by its round-trip impulse response on VHF channel after predetermined time delay.PAD4 sensing from the PING of MFG3, measure signal intensity and determine that it is in hazardous location, and by its round-trip impulse response on VHF channel after predetermined time delay.

Because MFG1 detects ECHO during time window W 1A on VHF channel, it is interpreted as instruction exists in the Label Field of PAD1 in its hazardous location.MFG1 also senses VHF signal and determines that PAD2 also exists in warning zone in time window W 1B.In its time window W 2A and W2B, period does not sense any ECHO to MFG2 on VHF channel arbitrarily, and reaches a conclusion and do not have PAD in its danger/warning zone in any one.MFG3 detects signal during time window W 3A, and reaches a conclusion and certainly have at least one PAD in its hazardous location.Because it is possible that irrelevant pulse appears in these time windows, MFG does not cause alarm state until receive ECHO in their identical time windows such as after at least two continuous P ING.

Referring now to Fig. 7, provide the details how chopping about PING and ECHO can regularly not conflict to make PING/ECHO exchange generation.Left half of 300 of Fig. 7 represent the PING/ECHO event for the PAD entered or in warning zone.Line 302 is timelines that the PING pulse 304 produced by MFG is shown.Line 306 is the timelines of the ECHO pulse 308 produced by PAD.Can occur afterwards from the predetermined delay 324 being less than a millisecond to several milliseconds according to ECHO pulse 308 of the present invention.Key element 310 is details of ECHO event, and the ECHO308 in ECHO event 320 is shown.ECHO event 320 was made up of the time period 330,332,334 and 336.ECHO event 320 represents the duration window of reception ECHO preset in MFG.Represent the short pulse from PAD at the ECHO bar 308 of ECHO event 320 inside, it must occur in the very first time part 330 of such as time window 320.

The PING/ECHO that the right side 320 of Fig. 7 represents for the PAD entered or in hazardous location exchanges.Notice ECHO328 in this example requires it is sufficiently long to occur in all time portion 330,332,334,336 of time window 320.Two additional PING304 and two additional ECHO328 is also shown.Three PING form burst, and wherein these PING can separate 1-10 millisecond.In the illustrated embodiment in which, after all three ECHO receive in time window, MFG and PAD arranges alarm.Because PING is very short, by the multiple PING of MFG generation per second, can guarantee that can make PING/ECHO exchanges and do not conflict.Statistical computation can be made to point out not from the high probability that the successful PING/ECHO of the conflict of neighbouring system exchanges.PING such as approximately on average can send once in the window of 0.050 and 0.250 second for every 0.125 second.

During first window not from two systems PING between the simple probability of successful exchange of conflict be 124/125.The probability successfully exchanged can not be made to equal (1/125) in complete one second ⁸, roughly 6 × 10 ^-16.Whenever considering multiple generator, many PAD, the potentially conflicting more between long pulse and ECHO for shape, even if the probability of successful exchanges in half second is very large, maintenance so makes greatly do not have any actual worry.Similarly, consider the requirement that the PING/ECHO of three completely randoms exchanges, the probability that false PING/ECHO occurs is very little.Test confirms extreme high reliability.That mentions before should noting does not affect ECHO about problems such as multipath, reflection, interference, because require it is only at the appointed time put the pulse receiving and specify the duration.

Notice that trucker 160 makes his PAD not arrange alarm and he freely leaves truck and does not enter warning zone 172 or hazardous location 174 in safety zone 134 in the diagram.Other workmans can not cause alarm near driver 160 to carry out face-to-face exchange.Can also for using the signal executive measure that falls back from truck systems with except when then close protection system outside when truck falls back, as what complete in the evaluation that describes in SAE:2007-01-4233.But, because the mode of safety zone 134 according to it limits, the needs of the protection that only falls back are reduced.In some cases, only when vehicle make when falling back system activate can produce unsafe state because truck be in reversing until it start movement backward time between may not always have very long delay.It is real for showing this to the safety message of death.Example is that vehicle stops making on the slope it can to start to fall back before clutch coupling closes the situation of movement.

With reference to Fig. 5, in operator monitor device 232, provide pot 228,230, operator monitor device 232 is typically arranged in the pilothouse of vehicle, and pot 228,230 is for reducing the size (if this expects) in magnetic field.In the shell of monitor, provide hole to make can insert screwdriver to make adjustment.The voltage obtained from the position of pot 228,230 is used as the input of microcontroller 202, and reduction (if necessary) made by microcontroller 202.This is reduced by the width of the 73kHz square-wave signal shortening driving amplifier 210,212,214 and completes in Control Component 200.By shortening these signals, less energy is input to resonant LC-circuit, thus is reduced by the average current of lc circuit and reduces the size in magnetic field.

Operator monitor device 232 place signal be available with the electric system at vehicle in use to slow down or stop vehicle (if this is applicable to particular vehicle in the specific work environments that this feature is desirable).To sound to warning or precarious position on the rear portion that additional lamp or warning horn can be arranged on truck.Lamp can be made with different frequency scintillations to distinguish alarm condition and precarious position.Similarly, warning horn can sound in different ways for identical object.PAD provides buzzer to increase progressively along with PAD enters warning zone further for warning the speed of wherein buzzer usually, then provides continuously buzzer or three times of fast buzzers to point out that it is in hazardous location.

System of the present invention can be installed near special hazard region, and this can be relevant with the ground condition of privileged site, and the people carrying PAD will be warned before entering region.This system also can be arranged in hazardous equipment and can to operate and hazardous equipment when people leans on too near will be stopped.Equipment can be stopped after the sound by listening or light give a warning to people or with it simultaneously.These warnings can by PAD or by the system be arranged on equipment or sent by both.The regional monitoring system of the type can be battery-operated, makes them be portable.

When PAD enters the hazardous location of restriction, the logic on order microcontroller adopts particular form operation, is called in alarm state.Once in this alarm state, it starts to perform once determine that PAD needs other functions performed in hazardous location.Movable alarm state is directly determined to sound which (if there is) alarm and/or which is taked other action (such as slow down or stop machine etc.) for protected machine.This system also understands other internal state information, such as, in response to the history of the ECHO of nearest PING reception.Only after multiple PING/ECHO sequence has confirmed that PAD is in dangerous region, this system enters higher alarm state.Only when passing by certain period of time period and it does not receive when pointing out that it should be retained in the ECHO of the type in the alarm state of raising in section during this period of time, this system enters lower alarm state.

The invention provides other features, itself and PING/ECHO are close to protection system collaborative work.Such as, data on a regular basis by RF link from PAD send with the information of the safety relating to workman is provided and allow during the emergency circumstance, follow the trail of workman, the latter needs most in underground mining.Equally, system provides the ability of the switch be used on PAD to make response to machine, machine operator or to send signal (especially during emergency condition) by other communication channels to workman.Also can get ready to use the RF link in PAD to send voice signal by increasing microphone to PAD, or transmission workman is obtainable and other information (life physical function (such as heart rate) of such as hazardous gas concentration, workman etc.) (by inputting this information to RF transmitter) of environment about workman.Follow the trail of node and can be placed on perform region to collect such information from PAD and to forward this information to other positions.Memory module is comprised with storage security relevant information for routine security evaluation or for the analysis after event at MFG.For underground mining application, during this can be included in emergency condition when being interrupted to the communication on ground by wear transmitter or send information to VLF or ULF by the MF transmitter in mine.PAD or TAG used together with PING/ECHO system can combine with the cap lamp assembly worn in underground mining and make them can extract electric power from that source.Other sensing apparatus can comprise and enter PAD/ cap lamp assembly to utilize RF transmittability, can carry power supply and microcontroller.

The present invention also can be used for when the speed of vehicle is enough slow (such as lower than about 20 feet per second (about 6 metre per second (m/s)s)) and avoids the collision between vehicle.In higher speed, the size providing the field that warning in time needs can be greater than the Label Field of generation.The size of Label Field can be limited because in order to the size of field double, for given input voltage, must be increased by the factor of eight by the electric current of inductor, it will require that great equipment is changed.PAD or another similar installation are placed on vehicle together with MFG.Circuit during the PING from MFG from MFG to PAD is used for PAD was lost efficacy.If PAD senses another vehicle in its warning zone or hazardous location, the operator of its warning vehicle.Signal from MFG may be used for slowing down or stop vehicle (if it is desirable).

There is the situation needing the driver vehicle of warning vehicle to stop near vehicle even without other workmans.Such as, when driver fall back truck to dump a little to height but gone too far and truck is stuck or worse drop on tipple outshot on time, by killing, other people are severely injured for many people.TAG can be placed on to dump a little when they should no longer retreat to allow driver know.Such TAG can also be positioned on entrucking parking area (loading dock) and the trucker when truck will contact parking area can be informed to, thus prevents the damage to truck and/or parking area.Then the vehicle that the operator of vehicle can go up them continually gets off again to perform various task.When on their vehicle or time middle, operator may not be in the danger injured by other equipment.But, when operator leaves vehicle, so operator can be exposed to the threat or dangerous and need protected from other vehicles.This special protection feature can be supplemented by the switch be used on PAD.

If workman is near the vehicle of the in harness operator of current not tool, this workman can Request System specify him to be operator.This is completed by the button pressed on the PAD being pressed in him when time in the warning zone at that machine.The PAD carried by that workman will send request the ID with this PAD.Then MFG by appointment this PAD be belong to operator's and send special burst get back to PAD simultaneously this button be depressed.This PAD will no longer report to the police and MFG also will ignore it.PAD will send its ID periodically, typically every 10 seconds, as a part for data set.As long as this PAD is retained in vehicle or on vehicle, another workman can not become the operator of this vehicle.If current operator leaves vehicle but returned before another operator is by this vehicle dispatch operator state, PAD will recognize this PAD still to be had operator's state and will not respond.

But each vehicle only can have an operator.If operator leaves this vehicle, data set is not received within the time period of the data set arrangement to the cycle, operator is shown still in Label Field, then operator's state of this PAD will be in time-out.If another workman asks operator's state of this vehicle, and operator before has halted state, new workman will be accepted as operator and operator before will lose his operator's state.If interrupted momently to the power supply of MFG, PAD can report to the police until send next data set or until operator is again by compressing switch.If operator is closed to the power supply of MFG and gets off, when another workman arrive or this operator return and solicit operation person's state time process will start anew.When the operator with PAD leaves the Label Field of vehicle (it has operator's state for this vehicle), PAD will in the normal fashion in response to other Label Fields.From operator's viewpoint, this process will be simple, substantial transparent.When operator is opened to the power supply of his vehicle, his PAD sounds starting.Operator press switch on PAD and by not provide warning and PAD by not in response to any PING from Label Field.

Above-mentioned explanation and figure are only the illustrative of the preferred embodiments of the present invention, and are not used to limit the invention in wherein.Its any purport in the spirit and scope falling into following patent requirement or change will think a part of the present invention.

Claims (7)

1. a method, comprises the steps:

Magnetic field is produced at the first predetermined amount of time;

Sense described magnetic field and produce response signal, when described alarm device detects the magnetic field of the first intensity, described response signal is very first time length, and described response signal is the second time span when described alarm device detects the magnetic field of the second intensity; And

Described response signal is sensed in the second predetermined amount of time;

Wherein said first intensity is different from described second intensity and described very first time length is different from described second time span,

Wherein, described method is used for collision free.

2. method according to claim 1, further comprising the steps:

Multiple vehicle is provided;

Multiple generator is provided, is eachly positioned at corresponding vehicle place and each for generation of corresponding magnetic field;

Multiple alarm device is provided, is eachly positioned at corresponding vehicle place and each for sensing magnetic field and producing response.

3. method according to claim 2, being included in described generator is further the step forbidding described alarm device during corresponding vehicle produces described magnetic field.

4. for complex work environment close to a detection method, it, for detecting the workman or the existence of operator in the potential danger position at work place place with multiple vehicle that carry alarm device, comprises the following steps:

For each of described vehicle provides multiple magnetic field generator, each of described multiple magnetic field generator is suitable for the ping pulse producing magnetic field;

The ping pulse in magnetic field is produced with magnetic field generator;

There is provided multiple alarm devices of the personnel being positioned at multiple workman and/or operator, each device is configured for the ping pulse in the magnetic field sensing described device place, and produces echo response signal after predetermined echo time delay;

Described multiple magnetic field generator receives described echo response signal; and receive described echo response signal in response to during the time window corresponding to predetermined echo time delay; produce bursting of magnetic field ping pulse, bursting described in ping pulse is bursting and producing with half random time intervals of predetermined lasting time;

Described multiple magnetic field generator, receive echo response signal in response to during the time window of each predetermined echo time delay of the ping pulse of bursting described in corresponding to, identify that described device is arranged in the specific magnetic fields produced by one of described multiple magnetic field generator.

5., for a method for complex work environment, it is for detecting the workman or the existence of operator in the potential danger position at work place place that carry alarm device, and described method comprises the following steps:

Each ping pulse producing first, second, and third magnetic field respectively of first, second, and third magnetic field generator; described first, second, and third magnetic field has overlapping region; and at each ping impulse duration with low-frequency oscillation, described ping pulse has the predetermined pulse duration and produces with the first half random time intervals;

Multiple alarm device; each device senses the intensity of the described ping pulsed magnetic field at described device place; and produce echo response signal after predetermined echo time delay, the length of wherein said predetermined echo time delay or the length of described echo response signal are based on the sensed intensities of described ping pulsed magnetic field;

Described first, second, and third magnetic field generator receives described echo response signal; and receive described echo response signal in response to during the time window corresponding to predetermined echo time delay; produce bursting of magnetic field ping pulse; bursting described in ping pulse is bursting and producing with the second half random time intervals of predetermined lasting time, and described the second half random time intervals are shorter than described the first half random time intervals;

Described first, second, and third magnetic field generator receives echo response signal in response to during the time window of each predetermined echo time delay of the described ping pulse of bursting described in corresponding to; identify that described device is arranged in described first, second and/or the 3rd magnetic field; and based on the length of described predetermined echo time delay or the length of described echo response signal; identify that described device is arranged in specific one of multiple regions in described first, second and/or the 3rd magnetic field, each region is less than described magnetic field;

Each alarm sending the first kind when it senses the first area in the described first or second magnetic field in described multiple alarm device, and each alarm sending Second Type when it senses the first area in described both first and second magnetic fields of wherein said multiple alarm device;

In wherein said multiple alarm device each when its sense described first and second magnetic fields one of at least instead of described 3rd magnetic field time give the alarm, and when it senses described 3rd magnetic field or senses described 3rd magnetic field, each of wherein said multiple alarm device adds that a period of time at least in described first and second magnetic fields does not give the alarm.

6. for complex work environment close to detection system in reduce the method for false alarm, it is for detecting the workman or the existence of operator in the potential danger position at work place place that carry alarm device, and described method comprises the following steps:

For each of described vehicle provides multiple magnetic field generator;

The ping pulse in each generation magnetic field of described multiple magnetic field generator, described magnetic field is at each ping impulse duration in low-frequency oscillation, and described ping pulse has predetermined lasting time and produces with the first half random time intervals;

Multiple alarm device, it is positioned on the personnel of multiple workman and/or operator, and each device senses the described ping pulsed magnetic field at described device place and produce echo response signal after predetermined echo time delay;

Described multiple magnetic field generator receives described echo response signal, and receive described echo response signal in response to during the time window corresponding to described predetermined echo time delay, produce bursting of magnetic field ping pulse, bursting described in ping pulse is bursting and producing with the second half random time intervals of predetermined lasting time, and described the second half random time intervals are shorter than described the first half random time intervals;

Described multiple magnetic field generator, described echo response signal is received in response to during the time window of each predetermined echo time delay of the ping pulse of bursting described in corresponding to, identify that described device is arranged in the specific magnetic fields of one of described multiple magnetic field generator generation, and

Only send alarm signal to described device and corresponding vehicle.

7. control, in the method close to the vehicle in detection system, to comprise the following steps:

Generator produces magnetic field, and this generator receives response signal; With

Alarm device senses described magnetic field and produces response signal;

Wherein, described generator generates described magnetic field at the first predetermined amount of time, and senses the response signal from described alarm device in the second time predefined section;

Wherein when described alarm device detects the magnetic field of the first intensity, described alarm device produces the response signal of very first time length,

Wherein when described alarm device detects the magnetic field of the second intensity, described alarm device produces the response signal of the second time span,

Wherein said first intensity is different from described second intensity and described very first time length is different from described second time span; And

When sensing the response signal of predetermined strength, described generator produces alarm signal to the concurrent number of delivering letters of operator of described vehicle to close down described vehicle.